Brushmaking machinery



Mmch 11, 1941 J. G. BAUMGARTNER 22349641 BRUSHMAKING MACHINERY Filed April 50, 1938 7 Sheets-Sheet l 'March 1l, 1941. J. G, BAUMGARTNER 2,234,641

BRUSHMAKING MACHINERY Filed April 50, 1958 '7 Sheets-Sheet 2 N N \\M\w/w /W W @n mn mnu m%\ www March 11, 1941- J. G. BAUMGARTNER I 2,234,641

BRUSHMAKING MACHINERY Filed April 30, 1958 7 Sheets-Shea?l 5 March 11, 1941 J. G. BAUMGARTNER 2,234,641

BRUSHMAKING MACHINERY Filed April 30, 1938 7 Sheets-Sheet 4 March 11, 19'41- J. G. BAUM'GARTNER 2,234,641

nusnmxma MACHINERY Filed April so, 1958 'I sheets-sheet 'T Patented Mar. 1l, 1941 PATENT OFFICE 2,234,641 xUsnMAmG MACHINERY John G. Baumgartner, Aurora, Ill., assignor to National Brush Company, Aurora, lll., a corporation of Illinois Application April 30, 1938, Serial No. 205,187

28 Claims.

This 'invention relates to machines for forming brushes of the type in which bristles are held between twisted wires, and it has been illustrated as embodied in a machine which is adapted in a single continuous and automatic operation to twist the bristle-holding portions'of the wires to the maximum degree of tightness and at the same time twist the extending portions of the wires tightly, but not so tightly as to break the same.

Wire twisting machines have been provided heretofore for twisting together two wires, between which the bristles of a brush are secured. Unless special care was taken, involving rather costly manual manipulations and loss of some bristles, such machines would make no difierentiation between the portions of the wires holding the bristles and the extending portions of the wires which are used for mounting the completed brush. In manufacturing low price brushes the practice has been to simply insert the ends of the wires in the twisting machine and twist the wires as much as was practicable in this manner. A characteristic of brushes twisted in this manner has been that the wires were too loosely twisted in the vicinity of the bristles, even though they were twisted unnecessarily tightly in the extensions. It so happens that the extensions twist much more readily than the bristle-holding portions, and before enough twisting force can be applied to twist the bristle-holding portions as tightly as desired, the extensions break. In the more expensive brushes this difficulty has heretofore been overcome by readjusting by hand the machine and the brush after a preliminary twisting so that the machine would grip the wires adjacent to the bristle-holding portions thereof so as to apply more twisting force to these portions of the wires than to the extensions. When the bristle-holding portions of the wires are twisted more tightly, they not `only hold the bristles more firmly but they bring the bristles so close together that the spiral effect in their positioning is not objectionable. Furthermore, a tightly twisted wire bends more smoothly and evenly than a loosely twisted wire when the brush is bent to the desired shape.

An object oi the present invention is to provide a machine which will manufacture the properly twisted brushes substantially as economically as the poorly twisted brushes have been manufactured heretofore. This is accomplished by providing a machine which automatically twists the central or bristle-holding portions of the wires independently of the extensions of the wires. More specifically. the machine includes two pairs of jaws at each end oi' the two wires. The inner pairs of jaws grip the wires adjacent the bristle-holding portions to twist these portions to the desired degree, after which they release and the outer jaws twist the extensions of the wires to the degree which is desired tor this portion of the wires.

Another object of the invention is to provide a machine 'in which the insertion of the Wires in the machine and the insertion of the bristles in the wires is facilitated. According to the present invention this is accomplished by providing clamps into which the wires may be easily inserted, causing a clamp at one endto clamp the wires rst in response to movement of a loot pedal, while leaving the other end free to permit the insertion ofthe bristles, and then clamping the other end in response to Ioot pedal control when the bristles are in place.

The advantages and objects of the invention will be made more apparent by the following description and by the drawings, in which:

Figs. l to are more or less diagrammatic views showing twisting operations. Fig. 1 shows the brush before twisting. Fig. 2 shows the brush after twisting of the central or bristle-holding portion. Fig. 3 shows the completed brush, the

inner jaws of the machine having been released while the outer jaws twisted the wire extensions. Fig. 4 shows a brush about to be twisted in a prior art machine with a single pair of jaws at each end. Fig. 5 shows the inferior result of this mode of twisting.

Fig. 6 is a diagrammatic view indicating the general operation of the entire machine of my invention.

Fig. i is a plan view of the wire twisting portion of the machine.

Fig, 8 is a view of the Reeves drive in high speed adjustment.

Fig. 9 is a view thereof in low speed adjustment.

Fig. 10 is an enlarged fragmentary longitudinal sectional view taken approximately on the line llll0 of Fig. 7.

Fig. 11is a perspective view (partially broken away) of the jaw unit within the twisting head for engaging the ends of the wires. Y

Fig. 12 is a fragmentary plan view on an en larged scale of the sliding but non-rotating wire holding carriage.

Fig. 13 is a sectional view taken approximately on the line Iii-1 3 ol' Fig. 12.

Fig. 14 is a fragmentary side elevation showing the construction of the valve controlling means.

Fig. 15 is a fragmentary plan view of the valve control mechanism.

Fig. 16 is a partly sectional view of the automatic control mechanism.

Fig. 17 is a view taken approximately on the line I'I-Ii of Fig. 18.

Although this invention may take numerous forms, only one has been chosen for illustration. It is believed that the construction will be understood more readily after. the purpose of the machine and its general mode of operation have been explained. As seen from.I Figs. l to 3, the purpose of the machine is to twist a brush blank. shown in Fig. 1, to the condition shown in Fig. 3. The brush blank includes a pair of lwires II, one of which is hidden behind the other in Fig. 1, and suitably arranged bristles I2 held between the wires. Two sets of Jaws are provided, the first set including the pairs I3 and I4 and the second set o f Jaws including the pairs I5 and I8. The laws I3 and I4 may be called medial jaws since they grasp the wires at inner or intermediate points. namely adjacent the bristle-holding portions thereof. The Jaws I8 and I8 may be called end Jaws since they grasp the wires at their ends.

General method of twisting During the ilrst portion of thetwisting operation all four pairs of jaws grasp the wires, and the jaws I3 and I8 are rotated jointly so that the wires are twisted between the Jaws I3 and I4, as indicated at Il. In the second portion of the twisting operation the Jaws I3 and I4 are released so that the rotation of jaws I5 twists the extensions I8 of the wires, i. e. the portions of the wires beyond the bristles. The twisting is stopped when the extensions I8 have been twisted to the desired degree, and since the twisting force required to reach this degree of twist in the extensions is less than that which was required to reach the desired degree of twist in the portions I'I in Fig. 2, the second step in the twisting has no effect on this portion Il.

A line 2| has been drawn across the portion I1 in Fig. 2 to indicate the pitch of the twist therein. A similar line 22 (Fig. 3) has been drawn on an extension I8 to indicate the pitch oi the twist in this portion`oi the wire. It will be observed that the pitch is approximately the same in each portion. This is desirable for various reasons. For the sake of simplicity of the drawings, the wire portions I'I have been illustrated in Figs. 2 and 3 as in contact although they would in fact be slightly separated by the bristles.

In Fig. 5, in which a brush is illustrated which has been twisted only by a single set of Jaws, i. e. one pair at each end, it is seen that the pitch shown by line 23 indicates less twist than the pitch of line 2| indicates, while the pitch indicated by line 24 indicates greater twist than does the pitch indicated by line 22. In other words, the simple method of twisting illustrated in Figs. 4 and 5 will twist the extensions I8' too tight while leaving the bristle-holding portion Il too loose. The extensions I8 may be twisted to the extent of being too tight and rigid or even to the extent of breaking without twisting the bristle-holding portion I1' as much as desired. When the bristle-holding portion Il is too loose, it does not bend smoothly and evenly. The convolutions of bristles are too far separated and the bristles may be insecurely fastened especially. after the brush has been bent to a desired shape.

General operation ol machine 'I'he general operation of the machine may be described with reference to Fig. 6. The operator iirst inserts the two wires II into the machine and he presses pedal I through the valve control system which will be described later. This causes the medial jaws I3 to close and grip the wires. I'he operator then nexes one wire away from the other and inserts the bristles I2 between the two wires, which bristles will have been previously arranged in a suitable clamp so that they may be inserted simultaneously and evenly. The operator then releases the sprung wire, and while holding the wires properly spaced to initially position them properly to prevent their breaking during the twisting, he presses pedal 2. This causes the other medial jaws I4 to close and in addition causes the end Jaws I8 and I8 to close. The operator then pushes pedal 3, which shifts clutch 3i so as to cause motor 32 to drive the twisting head 33 which includes both Jaws I3 and Jaws I6. This twists the bristle-holding portion Il-of the wires to the position shown in Fig. 2. While the twisting head 33 is being rotated, control shaft 34 is also being rotated, being connected to the twisting head 33 by any suitable means. As the bristle-holding portion Il reaches the twisted pitch shown in Fig. 2, the shaft 34 carries the trip arms 38 and. 31 into engagement with -trip levers 38 and 38 to cause the release of jaws I3 and I4 with the result that the further rotation of twisting head 33 twists the extensions I8 of the wires. When these have been twisted to the pitch shown in Fig. 3, the trip arm 4I engages the trip lever 42 to release latch 43 which has been holding pedal 3 depressed. The release of pedal 3 permits the clutch 3| to disengage so that the twisting of the wires ceases, and as the jaws I5 and I6 are now released the twisted brush may be removed.

Air control system Inasmuch as the jaws are controlled by compressed air, it is desirable at this point to describe the air control system. Depression of the pedal I actuates a cord 46 which in turn actuates a pivoted lever 41 to rotate cams 48 and 48 in a clockwise direction. Once actuated,.these cams are retained in their actuated positions by pawls 58 and 5I until the latter are released as will be described. The cams 48 and 48 operate valves 52 and 53 respectively. Details of construction are seen best in Figs. 14 and 15, although this description may be followed best in Fig. 6. The valve 52 admits compressed air to a conduit 54 which is connected to cylinder 55 which operates the jaws I3, closing these jaws when valve 52 is opened. Valve 53 admits air to a. conduit 51 which is connected to hollow shaft 34 to actuate a plunger 58 (Fig. 16) for thrusting the various trip arms 36, 31 and 4I to such a position that as they are rotated they will strike their respective trip levers 38, 38 and 42. The conduits may consist of or include flexible hosing to permit necessary movement of the connected parts. Pedal 2 actuates cord 59 which in like manner actuates pivoted lever 6I and cams 82 and 83 which are temporarily retained in their actuated positions by pawls 84 and 65. Cam 82 operates valve 61 which supplies air to cylinder 68 for closing jaws I4. Cam 63 actuates valve 89 forsupplying air cylinder 10 which closese Jaws Ii and to cyl- Y inder 1| which vcloses Jaws Il.

Near the end of the step of twisting the bristleholding portions I1 it is desirable to retard the rotating speed of the twisting head 3l so as to provide an interval of time for the jaws I3 and i4 to fully retract, so that they will not be in position to smash the bristles at the endsv of the I bristle-holding portion during the second portion of the complete twisting operation. Whenever it is desired to reduce the speed, such reduction is initiated by cam 1l which strikes the pin or cam follower 11 to actuate valve 1B, supplying air to flexible hose 19 and cylinder 8| ,which actuates a Reeves drive mechanism from the position shown in Fig. 8 to the position shown in Fig. 9 to Ichange the pulley ratio so as to reduce the speed of the twisting head 33.

'I'he next change that takes place occurs when the bristle-holding portions of the wires have been twisted the desired amount. At this time trip arm 36 strikes trip lever 38 to actuate cord 13' and thereby pivot pawl 50 to release cam 48 and allow valve 52 to close. shutting off the air from cylinder 58 and preferably opening a vent to permit the escape of air therefrom. In like manner the trip arm 31 strikes the trip lever 3B and actuates cord 14 and pawl 84 to release cam t2 and valve 01 to cut ofi the air pressure from cylinder B8 and permit jaws I4 to open.

'When the extensions of the wireshave been twisted to the desired degree, trip arm 4| strikes trip lever 42, thus actuating cord 82 and releasing latch 43 to permit the clutch 3| to shift to its released position. The trip lever 42 also actuates cord B3 to release pawl 5I and thus release cam 45 and valve 53, the latter cutting oil'. the supply of air to shaft 34 and plunger 58 and v opening a vent, thus permitting the shaft 34 itil to shift axially to its inactive position. This shifting of shaft 34 automatically releases it so that it may be returned to its original position under inuence of a weight 8E. It is stopped in this position by arm B1, but before it reaches this position the arm 81 acts as a trip arm to trip the lever B8 which actuates cord 39 for releasing pawl th. The release of pawl 65 releases cam 63 and valve B9 so that the latter-shuts oil the air and opens the vent to cylinders 10 and 1| to permit jaws IB and I to open. thus releasing the completely twisted brush. The time interval required for weight B6 to entirely rotate the arm 81 corresponds to the time interval required to stop the drive shaft. When arm 88 opens valve to release jaws, the shaft has stopped rotating. The ends of the wires then will be straight when they are released. If the jaws released while rotating, the ends ofthe wires would be partially caught and twisted out of a straight line. It is easier to put straight wire ends into the brush handle.

With thisknowledge of the operation of the machine as a whole the various parts thereof may -be described in detail for the purpose of aiding those skilled in the art in reproducing the same, although of course alternative forms of these parts could be provided without departing from the invention.

Twisting mechanism sliding carriage 9| which slides on slide rails I2,

being biased away from twisting head Il Vby a weight 93 Vwhich is connected to'sliding carriage 9| by a spring 94. Spring 04 functions to absorb the shock when the sliding carriage II reaches the end of its movement as determined by screws 95, which hold a stop plate 85' at their ends. a.

Thejaws I4and I8 do not rotate and therefore may be operated in a very simple manner. The operation of jaws I4 is seen' in Fig. 13, in which it is seen that one of the jaws I4 is iixed and the other is slldable. The position of fixed Jaw I4 is controlled by a screw 96 having a locknut 91. Movable Jaw I4 maybe pressed toward the fixed jaw I4 by operation of the cylinder 68 which actuates cam lever 98 to press the slidable jaw I4 with great force against the fixed jaw I4. Return springs 99 and |00 are provided for returning the cam lever 98 and movable jaws I4 to their Yoriginal positions when the air pressure is released.

The jaws I6 (Fig. l2) likewise include one fixed jaw and one movable `iaw.V The movable jaw in this instance may be pivoted and operated by a crank |0| connected to the cylinder 1o. Because the movable jaw I6 pivots and might therefore move the wires, it is preferred that the jaws I4 close first. This may be accomplished by having vthe valve 61 open slightly ahead of the valve E9, although it will be accomplished automatically if they open simultaneously since the-valve 68 controls two cylinders and has more conduit to be filled before the cylinders are fully actuated.

To facilitate the insertion of the wires between the jaws I4 vand I6 atable |03 may be provided on one side of the sliding carriage 9|, and a guide |04 may be provided on the other side of the carriage to guide the wires in between the jaws as` they are slid off of table IUS. In addition to this guide function for the table |03 and guide |04 they have the important function as safety devices to prevent the operator from catching his ngers in the brush or machine at this point.

When the jaws I4 are released from the wires it is necessary that they spring away from the bristles in order to permit the jaws I6 to be drawn toward the bristles as the extensions of the wires are twisted. To this end the jaws i6 are not mounted directly on the main carriage 9| but on a frame |08 which slides within the sliding carriage 9|. A spring ID1 urges the carriage |06 rearwardly to separate the pairs of jaws, but the weight 93 connected through spring 94 with the main' carriage 5| overpowers spring |01,` when the jaws I6 only are gripping the wires, and draws .carriage 9| away from the bristle-holding portions of the wires.

The remainder ofthe twisting machine is best seen in Fig. '1(l. The entire twisting head 33 is carried by a shaft member l I I which is journaled in a frame member IIZ. The shaft carries a large cylindrical end portion Ill Which in turn,

`ated by fingers ||9 which. as seen best in Fig. 7,

are operated by the cylinder 55. An antiiriction thrust bearing indicated by |20 may be provided.

within the cylindrical end portion m there is positioned a split cylindrical member 2| best seen in Fig. il. 'I'hls member carries the Jaws I8 which are pivoted to the sides of the cylinder' and a wedge-shaped actuator |22 arranged to operate the jaws I8 upon Alongitudinal movement. The longitudinal movement of the 'wedge |22 is accomplished by means of a rod |23. Tile A rod |23 runs within a. shaft |24 which carnal the split cylinder I2| at' one end and the air cylinder 1| at the other end. Within the air 'cylinder 1| the plungerlzs is rotatably seemed to the rod |23 and ris urged to the right as 'seen in Fig. by spring |21. g'lhs, when no thereby actuating jaws I8 and ilrmlyclamping in turn is carried by the shaft |24.

the wires II. Suitable antifriction bearingsmay be provided as indicated diagrammatically by the balls |28. To facilitate insertion of the wires,

jaws I3, the orifices of cap ||4, split cylinder'l2l, and jaws I8 are all beveled. The orflce in split cylinder I2I'is completed by guide pieces |28 between the ends of the split portions.

As in the case of jaws I4 and I8 it is necessary that the'jaws |3 and I5 contract after the'jaws |3 have released. In other words. it is necessary for the lawsv |3 to get out of the way ofthe bristles so as to permit contraction of the extensions i8 as it is twisted. 'Ihls relative contraction of the iaws I3 and i8 (or diminution of the space between theY two pairs of jaws) is accomplished bypermitting the jaws I8 to slide toward the jaws I3. vIt has already been seen that the jaws I8 are carried by the split cylinder |2| which This entire assembly, therefore, is urged to the right as seen in Fig. l0 by spring |3I. When the jaws I3 have been released, the weight 93 acting through the wires forming the brush and through jaws I5 will pull the entire assembly including jaws l5 to the left to the position shown in.Fig. 10. 'I'lle laws I3 are made to rotate with the twisting head 33 byvirtue of a key |32 secured to the split cylinder |2| and operating in a corresponding slot in the cylindrical member ||3.

1t le believed .that there is no need to describeY the construction ofthe clutch 3| in- Fig. 10 since any conventional clutch may be used. It should be noted, however, that in the illustrated form the spring |33 tends to press the clutch into engagement and that therefore the spring |34 must be sufilciently powerful to overcome the spring |33 and release the clutch when the latch 43 is released.

In Fig. 10 a portion of the drive for the control mechanism may also be observed. A pulley |38 is carried by the cylindrical member I I3 and keyed thereto. 'Ihis pulley drives a beltV |31 which drives a pulley |38. This pulley is connected through any suitable driving mechanism such as the universal joints and shafting |38 (Figs. l0 and 17) with a worm |4| which drives the worm gear |42 carried by shaft 34. Whenno air is supplied to shaft 34 through hose 81, shaft 34 is slid to. the left by a spring |43 so that lt is disconnected from gear |42 by virtue of the disengaged clutcb |44. When air is supplied to shaft 34, however. it reacts on plunger 83. compresses spring |43. drives the trip arms 38, 31 and 4| into vertical alinement with the trip levers 33. 38 and 42, and causes engagement of clutch |44 to connect shaft 34 with the gear |42.-l

As seen best in Fig. 17, each of the trip arms 38. 31 and 4| are adiustably secured on theshaft 34'by meam of la yoke |48 which may be tightened by a screw |41. The cam 18-may also be `adjustable with respect to the shaft as by being slotted and secured by screws |48. A bushing |48 which carries the stop arm 81 may also form a pulley for' winding up a cord |58 which' carries the weight 88 and is tied to arm 31.

Each of the trip levers 38, 38 and v42 pivots with respect to its supporting shaft I52 and is their return movement when the shaft 34 is in its left-hand position as seen in Fig. 16. In the forward movement of the trip arms 38, 31 and Vlimited in its return movement by a bar |83.

4| they together with the shaft 34 are in the `right-hand position and therefore they strike the ltrip levers 38, 38 and 42. The trip arm 81 is positioned in the opposite manner. It misses its trip lever 88 on its forward stroke and strikes it on the return stroke. 1

1 Speed changing mechanism As previously stated, the cam 18 ystrikes the pivoted cam follower 11 to open valve 18 and' best in Figs. 8 and 9. In Fig. 8 the parts areA in their high speed position and in Fig. 9 they are in their low speed position.

The speed change is accomplished by means of one form of Reeves drive mechanism. 'I'he twisting head is driven by a pulley I8| which is carried by shaft I. The-pulley I8| is driven by a belt |82 which in turn is driven by a split pulley comprising the beveled disc |83 and the beveled disc |84, .both of which are splined to the motor shaft |88 or a sleeve thereon. These discs are urged toward one another by a spring |81, the

tensionV of which may be regulated by a hand shown in Fig. atneshaft Iss is closest to the pulley I8| and hence the length of the belt |82 will permit the spring |81 to press the pulley portions |83 and |84toward one another as seen. in Fig. 7 so that the belt |82 rides near the periphery of the pulley portions |83 and |84. When air is supplied to theVv cylinder 8|, however, the table |1I is tilted to the position shown in Fig. 9 and the shaft y |88 is therefore moved farther away from the pulley I8| with the result that the belt |82 is drawn inwardly between the pulley portions |83 and |84, spreading these pulley portions apart so that the gielt gides near the centers thereof as seen in g. Y Y

Miscellaneous details unnecessary.

Self-adjustment for new brush One important detail oi' construction and operation which should be explained is that when the machine is at rest after one brush has been removed therefrom the various jaws will be in the proper longitudinal position to receive the wires for another brush. This is rather remarkable in view ofthe apparently irreconcilable fact that as soon as jaws I3 and I4 release during the twisting of the brush they snap toward the associated jaws I5 and I6 respectively so that they are not at that time, when they are apparently at rest, in position for receiving the wires for a new brush. However, it will be observed from Fig. lil that when the cylinder 'II has permitted the jaws |5 to release the wires II, the spring |3| will draw the split cylinder |2| and the jaws I5 to the right, so that they will be properly spaced apart for engaging the wires at the two desired points. Likewise, if the screws 35 are properly adjusted, the weight 93 will draw the carriage 8| to such a position that its jaws I4 are properly spaced from the jaws I3 ,for engaging the wires II just beyond the bristle-engaging portions thereof. Likewise, the spring |01 will draw the slide frame |06 to the left with respect to carriage 9|. This will space the jaws I6 the proper distance from the jaws I4 for the initial engagement of the wires. When the medial jaws I3 and I4 release, both or springs |01 and I3I will yield under the tension put on the wires by weight 93, to permit the medial' jaws to recede from the bristles.

The general operation was described at the first part of this description and therefore need not be repeated'here in detail. From the foregoing it is seen, however, that a machineis provided which facilitates the placing of the wires and the bristles in the machine and which, once they .have been placed, automatically twists the brush with a differential twisting force, applying a relatively great twisting force to the bristleholding portions of the wires until they are twisted to the desired pitch, and then restrictedly twisting the extensions oi' the wires, the twisting oi these extensions being automatically discontinued when they have been twisted to 4the desired pitch, even though the force required for twisting these extensions to this pitch is much less than the force required for twisting the bristle-holding portion of the brush to the desired pitch. After operation, the machine automatically returns to its original position so that it is ready to receive the wires for a new brush without further manual manipulation.

it should also be noted that no bristles are lost because during the entire twisting operation the bristles are kept centered on the wires by rotating against the usual guard plate iti. Heretofore when the wireswere differentially twisted the end bristles were often or usually dropped out while the uis/chine was stopped and the jaws were moved from the medial to the end positions. It should be explained that in order to keep the wires from breaking under the severe strain of twisting the bristle-holding portions of the wires, the twd wires are separated slightly in the clamps, and hence do not grip the end bristles tightly' even after the initial winding.

.although l have described my invention in its preferred embodiment, it is understood that it is not limited to this specific structure, but is limited only by the scope of the appended claims. The word jaws" is used to mean any two clamping members. The word bristles is used to mean any brush-forming members clamped between the wires Whether true bristles or not. Wires may be taken as meaning either two separate wires or two portions of a single doubled wire.

I claim:

1 Brush twisting apparatus for making a double-twisted wire brush in one automatic operation including a pair of opposed holding units each including two normally spaced pairs of jaws adapted to engage the wires of a brush, means for rotating the jaws in one of said units to twist the wires, and the jaws of one of the units being movable under tension longitudinally of the wires to permit the tensioned construction thereof as they are twisted, means for causing all of said jaws to originally engage the wires whereby the portion of the wires between the units willbe twisted independently of the remaining portion of the wires, means for causing only the end jaws to engage the wires whereby the portions between the jaws within the units will be twisted, and means for applying tension to the wires as they are twisted, the spaced pairs of jaws of one of said units moving relatively toward one another under the influence of said tension when the end jaws only grip the wires to permit foreshortening l of the wire originally between said pairs of jaws as it is twisted.

2*. Brush twisting apparatus for making a` vautomatically rendering the medial jaws ineffective after the bristle-holding portions of the wires have been twisted a predetermined degree with all jaws originally gripping said wires and said additional jaws maintaining said gripping continuously through a complete operation.

3. Brush twisting apparatus for making a double-twisted wire brush in one automotive operation including medial jaws adapted to grip the wires for a twisted wire brush adjacent the bristles thereof and relatively rotatable to twist the bristle-holding portion oi said wires, additional jaws adapted to engage the wires at points spaced from the bristles and relatively rotatable to twist the extensions of said wires when the iirst inentioned jaws are released, and means for automatically rendering the medial jaws ineffective after the bristle-holding portions of the wires have been twisted a predetermined degree and for thereafter rendering the end jaws ineffective to twist the wires further after the extensions have been twisted a predetermined degree with at least one of said jaws being continuously rotatabie throughout the twisting operation.

4. Brush twisting apparatus for making a double-twisted wire brush in one automatic operation including a pair of opposed holding units each including two normally spaced pairs oi jaws adapted to engage the wires of abrush, means for rotating the jaws in one of said units to twist the wires, and the jaws of one ci' the units being movable under tension longitudinally of the wires to permit the tensioned contraction thereof as they4 are twisted, means for causing all of said jaws to engage the wires whereby the portion. of

the wires between the units will be twisted inde pendently oi the remainder of the wires, means ior causing only the end jaws to engage the wires whereby the portions between the jaws within the units will be twisted, means for applying tension to the wires as they are twisted, the spaced pairs of jaws of one of said units moving relatively toward one another under the iniiuence of said tension when the end jaws only grip the wires to permit ioreshortening of the wires originally between said pairs of jaws as it is twisted, one of said units being mounted to move toward and from the other unit and having rst and second support members relatively movable in the same direction, one pair ci jaws being carried by each of said snpport members, and biasing means for biasing the movable unit away from the other unit, and drawing said pairs of jaws toward one another when only the jaws most remote from said other unit grip the wires and for separating the pairs of jaws when neither pair grips the wires.

5. Brush twisting apparatus including medial jaws adapted to grip the wires for a twisted wire brush adjacent the bristles thereof and relatively rotatable to twist the bristle-holding portions of said wires, additional jaws adapted to engage the wires at points spaced from the bristles and relatively rotating to twist the extensions of said wires, self-locking manually controlled means for causing one medial pair of jaws to grip the wires, self-locking manually controlled means for causing the other medial pair of jaws and the end pairs of jaws to grip the wires and to start the relative rotation of the jaws at opposite end portions of the wires, and automatically controlled means for causing the release of the locking means as to the medial jaws when the portions of the wires therebetween have been twisted a predetermined degree.

6. Brush twisting apparatus including medial jaws adapted to grip the wires for a twisted wire brush adjacent the bristles thereof and relatively rotatable to twist the bristle-holding portions of said wires, additional jaws adapted to engage the wires at points spaced from the bristles and relatively rotating to twist the extensions of said wires, self-locking manually controlled means for causing one medial pair of jaws to grip the wires, self-locking manually controlled means for causing the other medial pair of jaws and the end pairs of jaws to grip the wires and to start the relative rotation of the jaws at opposite end portions oi the wires, and automatically controlled j, means for causing the release of the locking means as to the medial jaws when the portions of the wires therebetween have been twisted a predetermined degree and for releasing the locking means as to tbe other jaws when the portions of the wires therebetween have been twisted to a predetermined degree.

7. Brush twisting apparatus including medial jaws adapted to grip the wires for a twisted wire means driven in a predetermined relationship with Y the relative rotation of the jaws for causing the release of the locieing means as to the medial jaws whe ions or i'he wires therebetween have been a Undetermined degree and for releasing the locleing means as to the other jaws when the portions of the wires therebetween have been twisted to a predetermined degree.

8. Erush twisting apparatus including medial jaws adapted to grip the wires for a twisted wire brush adjacent the b Lstles thereof and relatively rotatable to twist the bristle-holding portions of said wires, additional jaws adapted. to engage the wires at points spaced from the bristles, driving means for rotating one medial jaw and the associated additional jaw to twist the brush, and means eiective while said rotation continues for causing the medial jaws to disengage the wire to cause the portions of the wires therebeyond to be twisted.

9. Brush twisting apparatus including medial jaws adapted to grip the wires for a twisted wire brush adjacent the bristles thereof and relatively rotatable to twist the bristle-holding portions of said wires, additional jaws adapted to engage the wires at points spaced from the bristles, driving means for rotating one medial jaw and the associated additional jaw to twist the brush, means effective while said rotation continues for causing the medial jaws to disengage the wire to cause the portions of the wires therebeyond to be twisted, and means effective before the medial jaws release for changing the driving means to cause it to twist the wires with more speed and less force.

l0. Brush twisting apparatus including a wireholding unit having wire-holding means, and a twisting unit, including a. rst rotatable shaft, means for rotating the shaft, a head on the shaft having a.Y pair of jaws, a ring actuator for the jaws, means to operate said actuator as the shaft and jaws rotate, a second shaft keyed to and concentric with the first shaft and having a head including second jaws, a third shaft concentric with the other shafts, adapted at one end to actuate said second jaws and adapted at the other end to be actuated as said shafts and jaws rotate.

11,. Brush twisting apparatus including medial pairs of jaws adapted to grip the wires for a twisted wire brush adjacent the bristles thereof and relatively rotatable to twist the bristle-holding portions of said wires, additional jaws adapted to engage the wires at points spaced from the bristles and relatively rotating to twist the extensions of said wires whenthe first mentioned jaws are released, and treadle means for first causing one pair of jaws to engage the wires, and after a subsequent actuation causing the other jaws to engage the wires and the rotation of the jaws to commence.

12. The method of twisting a. brush in a continuous non-stopping operation which includes the steps of clamping a pair of wires slightly spaced apart in a pair of jaws, inserting bristles between the wires adjacent the jaws, clamping the wires in another pair of jaws adjacent the bristles and in a third pair of jaws spaced .from the bristles, rotating the jaws at one side of the bristles to twist the bristle-holding portions of the wires, while maintaining the bristles centered thereon, and releasing the jaws between the bristles and the third pair of jaws to cause the rotation to twist the portion of the wire between the bristles and the third pair of jaws with said rotation continuing during said releasing.

tion of the brush is arranged between said jaw units during the normal operation of said apparatus, said jaw units being relatively movable longitudinally and each of said units being comprised of an inner and an outer wire-gripping jaw with the inner jaw of each unit adjacent an end of the bristle portion with all of said jaws at one time gripping the wire being twisted, means for rotating one of said jaw units to twist the wire at the bristle portion, and means for releasing said inner gripping jaw in each unit after such twisting of the wires while maintaining the outer gripping jaws gripped to the wire, the twisting operation being continued with the outer gripping jaws to twist the wire laterally of the bristle portion to a predetermined twisted condition, with the inner and outer jaws of each jaw unit being relatively movable longitudinally and the inner jaws being longitudinally movable away from the bristle portion for the second twisting operation.

24. The method of twisting a double-twisted wire brush which includes the steps o' clamping wires in a pair of clamping means, inserting bristles between the wires adjacent said pair of clamping means, clamping the wires in a second pair of clamping means with said second pair of clamping means spaced longitudinally from the first pair of clamping means with the bristles arranged therebetween, rotating one of said pair of clamping means to twist the wires in an initial twisting operation, releasing one clamping means in each of said pair of clamping means while maintaining the second clamping means in each pair clamped to the wires, and twisting the wires in a second twisting operation.

25. The method of twisting a wire brush in two twisting operations, which method includes clamping brush wires between a pair of medial jaws and a pair of end jaws, twisting the wires in an initial twisting operation by-rotating one of the pair of medial jaws and an associated one of the pair of end jaws, releasing the medial jaws from said wires while maintaining the end jaws clamped to said wires, and twisting said wires in a second twisting operation by rotating one of said end jaws.

26. Apparatus for twisting a plurality of wires including frame means, a wire holding unit and a wire-twisting unit supported on said frame means, with the wire-twisting unit including a hollow rotatable shaft journalled in said frame means, a pair of jaws pivotally mounted on the outside of said hollow shaft, a second shaft supported within said hollow shaft, a second pair of pivotal jaws operatively connected to said second shaft and supported thereby, means on the outside of said hollow shaft for pivoting the first pair of jaws to apply a clamping pressure thereby, means on the inside of said hollow shaft for pivoting the second pair of jaws, with said first pair of jaws and said second pair of jaws being relatively longitudinally movable.

27. In apparatus as defined in claim 26 with the means on the outside of said hollow' shaft for pivoting the first pair of jaws including a substantially cone-shaped member longitudinally movable relative to said first pair of jaws for slidable engagement therewith, and with said means on the inside of the hollow shaft for pivoting the second pair` of. jaws including a wedgeshaped member longitudinally movable relative to said second pair of jaws and slidably engaging the saine.

28. Apparatus for twisting a plurality of wires including a plurality of .clamping jaws adapted to clamp and be lreleased from the wires in a predetermined cycle, and means for controlling and accomplishing the clamping and releasing including a shaft mounted for rotary and axial movement, a plurality of trip arms mounted on said shaft and movable therewith, a corresponding plurality of trip levers actuatable by said arms, iiuid means for shifting said shaft axially to bring said trip arms into radial alignment with said trip levers to actuate said levers upon rotary movement of said shaft, and means for moving said shaft axially to take said trip arms out of radial alignment with said trip levers to permit rotary movement of said arms with said shaft out of striking alignment with said levers.

JOHN G. BAUMGARTNER. 

